1. Field of the Invention
The present invention relates to work knives and, more particularly, work knives having multiple purposes including, without limitation, cutting, scraping, grouting, and plastering. The knife is further adapted to the particular needs of left handed workers as well as environments in which it would be advantageous to employ one""s left hand for a given purpose.
2. Prior Art
The Field of utility knives includes many examples of previous attempts, extending over many years, all of which are directed to the provision of a utility knife which satisfies one or more of the historic concerns associated therewith. These concerns include those of cost, safety, durability, and ergonomics, that is, compatibility with the human hand. A further need in the prior art is that for the storage of spare knife blades within the utility knife itself. A further need, however rarely addressed in the prior art, is that of a utility knife usable for many purposes and, as well, adaptable for use by workers which are both left and right handed.
The traditional trapezoidal-shaped, double-ended utility knife blade has been well known for over sixty years. See, for example, U.S. Pat. No. 2,145,985 (1939) to Krajecik. More recent efforts to improve upon the classical utility knife are reflected in U.S. Pat. No. 5,012,581 (1991) to Fletcher; U.S. Pat. No. 5,490,331 (1996) to Gold; U.S. Pat. No. 5,613,300 (1999) to Schmidt; U.S. Pat. No. 5,623,737 (1997) to Moyer; and U.S. Pat. No. 6,058,607 (2000) to Gringer.
None of this art, nor other art known to the within inventor, discloses a utility knife having a handle surface which is particularly proportioned to the human hand and the gripping function associated therewith when such a knife is held. Further, the prior art does not provide for a utility knife having integrated therewith a non-utility knife portion capable of both cutting and non-cutting functions. Also, the prior art does not provide for a multi-purpose utility knife having a portion thereof which may be selectably changed on the basis of whether or not the user is left or right handed or if a given work assignment, project or problem within a work environment is one in which a xe2x80x9cleftxe2x80x9d versus a xe2x80x9crightxe2x80x9d handed tool would be more advantageous for such a particular purpose.
The present invention addresses, in an integrated fashion, all of the above long felt needs that have existed in the art of utility knives.
A multi-purpose work knife, comprises a universal elongate handle (xe2x80x9cUEHxe2x80x9d) extending generally upon a UEH axis, said handle having a compound, convex curvature and an assembly within, at a top surface of a first end of said UEH, for holding a UEH utility knife blade in a selectable longitudinal position defined by a cutting edge of said UEH blade, said UEH also defining substantially oval radial cross-sections between said blade holding assembly and a second end thereof, said cross-sections defining slightly smaller radii at about a center region of said UEH, said second end comprising complemental securement means; and a selectable non-universal portion (xe2x80x9cSNPxe2x80x9d) having a first end and a second end, said second end comprising means for selectable complemental securement to said UEH complemental securement means, said second end of said SNP having a like radius and curvature to said second end of said UEH at opposing surfaces thereof, said UEH axis passing through said complemental securement means of said surfaces of said second ends of said UEH and SNP respectively, said SNP further comprising, at a first end and top surface thereof, an assembly for selectably holding a knife blade having a cutting edge projecting away from said first end of said SNP, in which said cutting edge of said SNP blade defines an angle which intersects said axis of the UEH blade, at a virtual extension external to said work knife, in a range of about 20 to about 40 degrees. Said SNP may selectably take several forms including a left angled axis relative to the axis of the UEH, a right angled axis relative thereto, and an axis substantially co-linear with said UEH axis.
It is an object of the invention to provide a multi-purpose work knife having a universal portion corresponding to the classical function of a utility knife and having a non-common portion which provides for adaptability of the knife to the needs of left versus right handed persons and, as well, affords numerous additional cutting and non-cutting functions.
It is another object to provide a multi-purpose work knife of the above type having a surface curvature and geometry particularly adapted for the requirements of the human hand during the gripping of a utility knife.
It is thereby a further object of the invention to provide an improved multi-purpose knife which is usable with equal facility by both left-handed and right-handed persons.
It is a still further object to provide a work knife which, alternatively, may be employed in numerous non-utility cutting and non-cutting applications.
The above and yet other objects and advantages of the present invention will become apparent from the hereinafter set forth Brief Description of the Drawings, Detailed Description of the invention and claims appended herewith.